无法打开流:HTTP请求失败！检测到HTTP/1.1 508循环

我正在制作一个Php Web服务，从httpurlconnection读取OutputStream。我有一个android应用程序，它创建了到网站的httpurl连接，并将json字符串写入OutputStream。现在我想通过Web服务读取/获取json。但我总是遇到这样的错误：

failed to open stream: HTTP request failed! HTTP/1.1 508 Loop Detected

我将提供有关我申请的所有信息。如果有人知道发送和接收数据的更好方法，请随时欢迎！

我的android应用程序在出现onclick事件时发送数据，然后使用AsyncTask。这是代码：

public void clickbuttonRecieve(View v) {
    MyAsync performBackgroundTask = new MyAsync();
    performBackgroundTask.execute();
}

protected Void doInBackground(Void... tmps) {
        try {
            // instantiate the URL object with the target URL of the resource to
            // request
            URL url = new URL("http://bomatec.be/webservice2.php");
            // instantiate the HttpURLConnection with the URL object - A new
            // connection is opened every time by calling the openConnection
            // method of the protocol handler for this URL.
            // 1. This is the point where the connection is opened.
            HttpURLConnection connection = (HttpURLConnection) url
                    .openConnection();
            // set connection output to true
            connection.setDoOutput(true);
            // instead of a GET, we're going to send using method="POST"
            connection.setRequestMethod("POST");
            // instantiate OutputStreamWriter using the output stream, returned
            // from getOutputStream, that writes to this connection.
            // 2. This is the point where you'll know if the connection was
            // successfully established. If an I/O error occurs while creating
            // the output stream, you'll see an IOException.
            OutputStreamWriter writer = new OutputStreamWriter(
                    connection.getOutputStream());
            // write data to the connection. This is data that you are sending
            // to the server
            // 3. No. Sending the data is conducted here. We established the
            // connection with getOutputStream
            JSONObject data = new JSONObject();
            data.put("user", "12");
            data.put("lat", "50.8");
            data.put("lng", "4.3");
            String json = data.toString();
            writer.write("json=" + json);
            // Closes this output stream and releases any system resources
            // associated with this stream. At this point, we've sent all the
            // data. Only the outputStream is closed at this point, not the
            // actual connection
            writer.close();
            // if there is a response code AND that response code is 200 OK, do
            // stuff in the first if block
            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                // OK
                // otherwise, if any other status code is returned, or no status
                // code is returned, do stuff in the else block
            } else {
                // Server returned HTTP error code.
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        } catch (JSONException e) {
            e.printStackTrace();
            return null;
        }
    }
}

我的网络服务应用程序包含以下代码：

header('Content-Type: application/json');
$json = file_get_contents('http://bomatec.be/webservice2.php?');
$obj = json_decode($json);
echo json_encode(array('json'=>$obj));
echo $json;

当我运行网络服务器时，例如：

http://bomatec.be/webservice2.php?json={%22user_id%22:31,%22lat%22:50.78,%22lng%22:2}

我得到以下错误：

{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}{"json":null}<br />
<b>Warning</b>:  file_get_contents(http://bomatec.be/webservice2.php?): failed to open stream: HTTP request failed! HTTP/1.1 508 Loop Detected
 in <b>/home/bomate1q/public_html/webservice2.php</b> on line <b>15</b><br />
{"json":null}

我不知道怎么解决这个问题。我迷失在其中。